Magnetic solid lipid nanoparticles as mediators for controlled hyperthermia

This paper presents the development of magnetic lipid nanoparticles that could serve as targeting delivery vehicles and heat targeted cells in a desired manner. The nanoparticles are composed of lipid matrices with low melting temperatures and fabricated by high-pressure emulsification processes at raised temperatures. Super-paramagnetic gamma-Fe₂O₃ particles with sizes ranging from 5 to 25 nm are surface modified and dispersed evenly in the lipid nanoparticles. In the prototype demonstration, lipid nanoparticles with average sizes between 100 and 180 nm were fabricated. Meanwhile, roughly 40% to 65% of the dispersed iron oxide remained in the resulting lipid nanoparticles. When exposed to an alternating magnetic field of 60 kA/m at 25 kHz, a solution with 2 g/L encapsulated gamma-Fe₂O₃ particles showed a temperature rise from 37 to 50degC in 20 minutes. As such, the presented solid lipid nanoparticles pioneer a new scheme of targeted and magnetically controlled hyperthermia, which is potentially applicable to a variety of medical treatments.